Piping Fabrication Procedure

Piping Fabrication Procedure:

1. Marking shall be done according to drawing requirement and the same shall be checked by concerned supervisor prior to cutting.
2. The cutting shall be generally done as follows:

                                          i.    Carbon Steel pipes          -          By gas cutting & grinding.

                                        ii.    Alloy Steel pipes              -          By grinding or flammable cutting.

                                       iii.    Stainless Steel Pipes       -          By grinding or plasma cutting.

3. Before cutting the pipe Heat Number will be transferred to the cut pieces by low stress dye stamping, Paint marking or Tagging.
4. End preparation and fit-up shall be done at shop as per the approved Specification and WPS.
5. Care shall be taken to make sure that longitudinal seams on the joining pipes will not come in one line in a butt joint. Seams will be staggered at least 100mm apart and also will clear the branch connections. Care shall be taken to make sure that longitudinal seams are not resting on the steel structure.
6. Pipes and Fittings for fit-up will be placed on temporary pipe bed and will make sure that supports are secured properly.
7. Welding of the joint will be done after getting QC fit-up Inspection clearance and the same shall be offered for Client inspection randomly.
8. All flange connected to equipment shall be tack welded only.
9. Line No, Component Heat No., Joint No., Fit-up inspection signature, Welder No., Visual inspection signature and date of welding will be marked near to the joint with metal paint marker.
10. Spool No. will be marked with paint marker and aluminum tag will be tied to the spool. Fabrication completed spools will be shifted from shop to lay down area.
11. NDT shall be performed as required by Project specification. After NDT clearance, spools shall be released for erection / painting with release notice.
12. NDT rejected spools will be identified with yellow I black tag and the repair will be done immediately and NDT will be executed on repaired weld areas as required.
13. After painting, field inspection shall be offered for QC and the same shall be QC recorded in the prescribed format.
14. After painting inspection, the spool shall be released for erection.
15. Stainless Steel fabrication will be done in the shop with an isolated area from carbon steel and alloy steel.
16. No tools, tackles, equipment will be used for SS which has been used for CS. All tools and equipment dedicated to SS work shall be clearly marked "For Stainless Steel" only.
17. For Stainless steel materials, stainless steels tools will be used for grinding, brushing and clamping etc.
18. Pre heating and PWHT will be done at shop and field as per specification requirements.
19. All flanged raised faces of completed spools will be fitted with plywood blinds for protection and spool ends shall be fitted with proper caps         

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